Are you sure that the demand on L2ARC is sufficient to create that I/O rate? Do other devices for L2ARC provide a higher rate for the same work load?
Sanjay On Fri, Aug 24, 2018, 10:29 AM w.kruzel via openzfs-developer < [email protected]> wrote: > Thanks, Sanjay - I will try running it on FreeBSD and will post some flame > graphs here. > > Maybe I am doing it wrong but I am using NVMe for primary storage and ass > tons of ram for arc. > > In my case we went for capacity, and planning on having 36x10TB disks. > With the initial stage of 12x10TB disks, while the NVMe cache is supposed > to give us 2TB of quick cache. > > I think L2ARC is relegated to the highly budget oriented plays these days > as RAM is soooo cheap. Buy some more ram and fooor-get-about it. > > Well, this is still in the order of magnitude, whether you get hardware > that costs tens of thousands or hundreds of thousands $/£/€. > > L2ARC uses the ZIO pipeline, just like everything else. Very parallel. But if > your workload isn’t parallel, then... > -- richard > > I'm interested it what difference it makes to read a file directly from > nvme and get 2GB/s+ and then when the same nvme disk is used via L2ARC, it > only gets 200MB/s read speeds. > Whether read from file system is multi threaded and read on L2ARC single > threaded. > > -Wojciech > *openzfs <https://openzfs.topicbox.com/latest>* / openzfs-developer / see > discussions <https://openzfs.topicbox.com/groups/developer> + participants > <https://openzfs.topicbox.com/groups/developer/members> + delivery options > <https://openzfs.topicbox.com/groups/developer/subscription> Permalink > <https://openzfs.topicbox.com/groups/developer/Tf62628db027682f7-Maff4e6d5afd156fcbe85b045> > ------------------------------------------ openzfs: openzfs-developer Permalink: https://openzfs.topicbox.com/groups/developer/Tf62628db027682f7-M3a19a77739ed2e9d6aed1f85 Delivery options: https://openzfs.topicbox.com/groups/developer/subscription
